fix wrong src_id and dst_id

This patch is similar with Pull Request #64 .
Make every line of edge file contains only two elements which are src_id and dst_id. Before this modification, there are three which are src_id, src_id and dst_id.
Pagerank can run multiple iterations now with this modification. Have tested it.
Since we do not need `from` here, delete the definition of `from` in line 245 also. And you may find that you should also include the jar file in your commit.